Apparatus and method for maintaining an article at a temperature that is less than the temperature of the ambient air

Abstract

An apparatus for maintaining the temperature of an article at a temperature that is below the ambient air temperature includes an enclosure having an outer wall that defines an interior chamber for holding a volume of sealed air. An insert is disposed inside of the chamber and has a body that is made of a porous graphite foam material. A vacuum pump penetrates the outer wall and fluidly connects the sealed air in the interior chamber with the ambient air outside of the enclosure. The temperatures of the insert and article is maintained at temperatures that are below the ambient air temperature when a volume of a liquid is wicked into the pores of the porous insert and the vacuum pump is activated to reduce the pressure of a volume of sealed air within the interior chamber to a pressure that is below the vapor pressure of the liquid.

What is claimed is: 
     
       1. An apparatus for maintaining the temperature of an article at a temperature that is less than the temperature of the ambient air outside of the apparatus comprising:
 an enclosure having an outer wall and a lid that define an interior chamber for holding a volume of sealed air, said enclosure insulates the interior chamber from the ambient air that is outside said enclosure; 
 an insert disposed inside of the interior chamber, said insert having a body that is made of a porous graphite foam material and having a region for contacting the article; 
 a vacuum pump penetrating through the enclosure, said vacuum pump fluidly connecting the sealed air in the interior chamber with the ambient air outside of said enclosure; and 
 wherein the temperatures of said insert and of the article are maintained at temperatures that are below the ambient air temperature when a volume of liquid is wicked into the pores of the porous graphite foam insert and said vacuum pump is activated to reduce the pressure of the sealed air within the interior chamber to a pressure that is below the vapor pressure of the liquid. 
 
     
     
       2. The apparatus of  claim 1  wherein said outer wall comprises ceramic microspheres. 
     
     
       3. The apparatus of  claim 1  wherein said enclosure comprises a body and a lid and, together with a gasket, the body, the lid and the gasket create a hermetic seal when assembled together. 
     
     
       4. The apparatus of  claim 1  wherein said vacuum pump is a manually operated vacuum pump. 
     
     
       5. The apparatus of  claim 1  and further comprising a temperature gauge penetrating the enclosure and having a sensing element for contacting said insert and an indicating element for displaying the temperature of said insert at a position that is viewable outside of said enclosure. 
     
     
       6. The apparatus of  claim 1  and further comprising a vacuum pressure gauge penetrating the enclosure for monitoring and displaying the pressure of the sealed air in the interior chamber. 
     
     
       7. The apparatus of  claim 1  wherein, when the vacuum pump is activated, the sealed air pressure within the interior chamber is maintained at between approximately 5.2 torr (mmHg) and 8.0 torr (mmHg). 
     
     
       8. The apparatus of  claim 1  wherein when a volume of liquid is wicked into the pores of the porous insert, the liquid is water. 
     
     
       9. A method for maintaining the temperature of an article at a temperature that is less than the temperature of the ambient air comprising the steps of:
 a) providing an enclosure having an outer wall and a lid that define an interior chamber containing a volume of sealed air, said enclosure insulates the chamber from the ambient air, an insert disposed inside the chamber, said insert having a body that is made of a porous graphite foam material and including a region for contacting the article, and a vacuum pump penetrating the enclosure, said vacuum pump fluidly connecting the sealed air within the interior chamber with the ambient air outside of said enclosure; 
 b) positioning an article inside said enclosure and in contact with said insert at a contacting region; 
 c) wicking a volume of a liquid into at least a portion of the pores of the porous insert; 
 d) sealing said enclosure; and 
 e) activating said vacuum pump to reduce the pressure of the sealed air within the interior chamber to a pressure that is below that of the vapor pressure of the liquid, such that the liquid evaporates, causing the temperatures of said insert and of the article to be maintained at temperatures that are below the ambient air the temperature outside of the enclosure. 
 
     
     
       10. The method of  claim 9  wherein the providing step a) includes an outer wall comprising ceramic microspheres. 
     
     
       11. The method of  claim 9  wherein the sealing step d) includes assembling a lid and a gasket to a body of said enclosure to create a hermetic seal. 
     
     
       12. The method of  claim 9  wherein the activating step e) includes manually pumping said vacuum pump. 
     
     
       13. The apparatus of  claim 9  wherein the activating step e) includes maintaining the sealed air pressure within the interior chamber at a pressure that is between approximately 5.2 torr (mmHg) and 8.0 torr (mmHg) with said vacuum pump. 
     
     
       14. The method of  claim 9  and further comprising the step of:
 f) monitoring the temperature of said insert with a temperature gauge penetrating through said enclosure and having a sensing element for contacting said insert and an indicating element for displaying the temperature of said insert outside of said enclosure. 
 
     
     
       15. The method of  claim 9  wherein the activating step e) further includes monitoring a vacuum pressure with a vacuum pressure gauge penetrating through said enclosure that is indicative of the vacuum pressure of the sealed air in the interior chamber. 
     
     
       16. The apparatus of  claim 9  wherein the wicking step c) includes wicking a volume of water into the pores of the porous insert. 
     
     
       17. A human-powered refrigeration system comprising:
 a hermetically sealed enclosure defining an interior chamber for holding a volume of sealed air; 
 an insert made of porous graphite foam disposed in the interior chamber; 
 a volume of a liquid wicked inside said porous graphite foam insert; 
 a manual vacuum pump for reducing the pressure of the sealed air within the interior chamber; and 
 wherein the temperature of the insert is maintained at a temperature that is less than the temperature of the ambient air outside of the enclosure when a human activates the manual vacuum pump to reduce the pressure of the volume of sealed air within the interior chamber to a pressure that is below the vapor pressure of the liquid. 
 
     
     
       18. The system of  claim 17  wherein the liquid is water. 
     
     
       19. The system of  claim 17  wherein the sealed air pressure within the interior chamber is maintained at a pressure that is between approximately 5.2 torr (mmHg) and 8.0 torr (mmHg) with said vacuum pump. 
     
     
       20. The apparatus of  claim 17  wherein said enclosure includes and outer wall that comprises ceramic microspheres.